1. Field of the Invention
The invention relates to a method for testing the fit or imbalance of a tool which is accommodated in a replaceable manner in a tool spindle mounted so that it may be driven in rotation about a central longitudinal axis.
A tool spindle of this type is used in a machine tool. In order to achieve high machining accuracy, the inserted tool should run as true as possible. Deviations from concentricity may result due to a non-aligning fit, caused by contaminants, of the tool in the tool spindle or due to some types of tool imbalances. Such irregularities are to be detected and rectified.
2. Background Art
It is known from U.S. Pat. No. 6,059,702 to clean the abutment surfaces with compressed air or with the cooling means of the machine tool when the tool is inserted. Moreover, it is possible to check the correct, i.e. aligning fit of the tool, following insertion, by introducing compressed air and by detecting the resulting reduction in pressure. However, a separate pressure measuring device is required for this purpose. The checking procedure also takes a relatively long time, since the drop in pressure to be analysed generally only takes place slowly.
Furthermore, WO 97/31751 A1 discloses a method for avoiding thermally induced changes in position of the tool using a light barrier comprising a transmitter and a receiver. The fit or imbalance is not tested in this method.